Boosting C–C coupling to multicarbon products via high-pressure CO electroreduction

Electrochemical CO reduction reaction(CORR) provides a promising approach for producing valuable multicarbon products(C_(2+)), while the low solubility of CO in aqueous solution and high energy barrier of C–C coupling as well as the competing hydrogen evolution reaction(HER) largely limit the efficiency for C_(2+)production in CORR. Here we report an overturn on the Faradaic efficiency of CORR from being HER-dominant to C_(2+)formation-dominant over a wide potential window, accompanied by a significant activity enhancement over a Moss-like Cu catalyst via pressuring CO. With the CO pressure rising from 1 to 40 atm, the C_(2+)Faradaic efficiency and partial current density remarkably increase from 22.8%and 18.9 mA cm^(-2)to 89.7% and 116.7 mA cm^(-2), respectively. Experimental and theoretical investigations reveal that high pressure-induced high CO coverage on metallic Cu surface weakens the Cu–C bond via reducing electron transfer from Cu to adsorbed CO and restrains hydrogen adsorption, which significantly facilitates the C–C coupling while suppressing HER on the predominant Cu(111) surface, thereby boosting the CO electroreduction to C_(2+)activity.

Calcineurin B-like interacting protein kinase OsCIPK23 functions in pollination and drought stress responses in rice (Oryza sativa L.)

Drought is very harmful to grain yield due to its adverse effect on reproduction, especially on pollination process in rice. However, the molecular basis of such an effect still remains largely unknown. Here, we report the role of a member of CBL （Calcineurin B-Like） Interacting Protein Kinase （CIPK） family, OsCIPK23, in pollination and stress responses in rice. Molecular analyses revealed that it is mainly expressed in pistil and anther but up-regulated by pollination, as well as by treatments of various abiotic stresses and phytohormones. RNA interference-mediated suppression of OsCIPK23 expression significantly reduced seed set and conferred a hypersensitive response to drought stress, indicating its possible roles in pollination and drought stress. In consistent, overexpression of OsCIPK23 induced the expression of several drought tolerance related genes. Taken together, these results indicate that OsCIPK23 is a multistress induced gene and likely mediates a signaling pathway commonly shared by both pollination and drought stress responses in rice.

Recent progress of precious-metal-free electrocatalysts for efficient water oxidation in acidic media

The realization of efficient oxygen evolution reaction(OER) is critical to the development of multiple sustainable energy conversion and storage technologies, especially hydrogen production via water electrolysis. To achieve the massive application of hydrogen energy and mass-scale hydrogen production from water splitting drives the pursuit of competent precious-metal-free electrocatalysts in acidic media, where the hydrogen evolution reaction(HER) is more facilitated. However, the development of high-efficient and acid-stable OER electrocatalysts, which are robust to function stably at high oxidation potentials in the acidic electrolyte, remains a great challenge. This article contributes a focused, perceptive review of the up-to-date approaches toward this emerging research field. The OER reaction mechanism and fundamental requirements for oxygen evolution electrocatalysts in acid are introduced. Then the progress and new discoveries of precious-metal-free active materials and design concepts with regard to the improvement of the intrinsic OER activity are discussed. Finally, the existing scientific challenges and the outlooks for future research directions to the fabrication of emerging, earth-abundant OER electrocatalysts in acid are pointed out.

Laser-Induced Recoverable Fluorescence Quenching of Perovskite Films at a Microscopic Grain Scale

Understanding the fundamental properties of metal-halide perovskite materials is driving the development of novel optoelectronic applications.Here,we report the observation of a recoverable laser-induced fluorescence quenching phenomenon in perovskite films with a microscopic grain-scale restriction,accompanied by spectral variations.This fluorescence quenching depends on the laser intensity and the dwell time under Auger recombination dominated conditions.These features indicate that the perovskite lattice deformation may take the main responsibility for the transient and show a new aspect to understand halide perovskite photostability.We further modulate this phenomenon by adjusting the charge carrier recombination and extraction,revealing that efficient carrier transfer can improve the bleaching resistance of perovskite grains.Our results provide future opportunities to attain high-performance devices by tuning the perovskite lattice disorder and harvesting the energetic carriers.

Advances in Research of Pharmacological Activities of Resveratrol

Resveratrol is a non-ketone polyphenolic compound containing a stilbene structure.It exists in many common medicinal plants.It has many pharmacological activities such as anti-tumor,antioxidant,antibacterial and cardiovascular protection.In this paper,the advances in research of pharmacological activities of resveratrol in recent years were reviewed,to provide a reference for its further development and utilization.

GreenPhos,a universal method for in-depth measurement of plant phosphoproteomes with high quantitative reproducibility

Protein phosphorylation regulates a variety of important cellular and physiological processes in plants.In-depth profiling of plant phosphoproteomes has been more technically challenging than that of animal phosphoproteomes.This is largely due to the need to improve protein extraction efficiency from plant cells,which have a dense cell wall,and to minimize sample loss resulting from the stringent sample clean-up steps required for the removal of a large amount of biomolecules interfering with phosphopeptide purification and mass spectrometry analysis.To this end,we developed a method with a streamlined workflow for highly efficient purification of phosphopeptides from tissues of various green organisms including Arabidopsis,rice,tomato,and Chlamydomonas reinhardtii,enabling in-depth identification with high quantitative reproducibility of about 11000 phosphosites,the greatest depth achieved so far with single liquid chromatography-mass spectrometry(LC-MS)runs operated in a data-dependent acquisition(DDA)mode.The mainstay features of the method are the minimal sample loss achieved through elimination of sample clean-up before protease digestion and of desalting before phosphopeptide enrichment and hence the dramatic increases of time-and cost-effectiveness.The method,named GreenPhos,combined with single-shot LC-MS,enabled in-depth quantitative identification of Arabidopsis phosphoproteins,including differentially phosphorylated spliceosomal proteins,at multiple time points during salt stress and a number of kinase substrate motifs.GreenPhos is expected to serve as a universal method for purification of plant phosphopeptides,which,if samples are further fractionated and analyzed by multiple LC-MS runs,could enable measurement of plant phosphoproteomes with an unprecedented depth using a given mass spectrometry technology.

Characteristics of N^(6)-methyladenosine Modification During Sexual Reproduction of Chlamydomonas reinhardtii

The unicellular green alga Chlamydomonas reinhardtii(hereafter Chlamydomonas)possesses both plant and animal attributes,and it is an ideal model organism for studying fundamental processes such as photosynthesis,sexual reproduction,and life cycle.N^(6)-methyladenosine(m^(6)A)is the most prevalent mRNA modification,and it plays important roles during sexual reproduction in animals and plants.However,the pattern and function of m^(6)A modification during the sexual reproduction of Chlamydomonas remain unknown.Here,we performed transcriptome and methylated RNA immunoprecipitation sequencing(MeRIP-seq)analyses on six samples from different stages during sexual reproduction of the Chlamydomonas life cycle.The results show that m^(6)A modification frequently occurs at the main motif of DRAC(D=G/A/U,R=A/G)in Chlamydomonas mRNAs.Moreover,m^(6)A peaks in Chlamydomonas mRNAs are mainly enriched in the 30 untranslated regions(30 UTRs)and negatively correlated with the abundance of transcripts at each stage.In particular,there is a significant negative correlation between the expression levels and the m^(6)A levels of genes involved in the microtubule-associated pathway,indicating that m^(6)A modification influences the sexual reproduction and the life cycle of Chlamydomonas by regulating microtubule-based movement.In summary,our findings are the first to demonstrate the distribution and the functions of m^(6)A modification in Chlamydomonas mRNAs and provide new evolutionary insights into m^(6)A modification in the process of sexual reproduction in other plant organisms.

线性常微分方程的全局误差估计和优化求解方法

线性常微分方程初值问题求解在许多应用中起着重要作用.目前,已存在很多的数值方法和求解器用于计算离散网格点上的近似解,但很少有对全局误差(global error)进行估计和优化的方法.本文首先通过将离散数值解插值成为可微函数用来定义方程的残差;再给出残差与近似解的关系定理并推导出全局误差的上界;然后以最小化残差的二范数为目标将方程求解问题转化为优化求解问题;最后通过分析导出矩阵的结构,提出利用共轭梯度法对其进行求解.之后将该方法应用于滤波电路和汽车悬架系统等实际问题.实验分析表明,本文估计方法对线性常微分方程的初值问题的全局误差具有比较好的估计效果,优化求解方法能够在不增加网格点的情形下求解出线性常微分方程在插值解空间中的全局最优解.

豆科饲草碳氮高效固定、转运和同化利用研究进展

近年来,我国对优质饲草的需求不断增长。提高各种饲草尤其是紫花苜蓿(Medicago sativa)的产量和品质是饲草生物学研究领域一项重要的科研和经济目标。光合作用固定二氧化碳是牧草生物量形成的基础;氮素的吸收、固定、转运和同化则是影响牧草粗蛋白含量并决定其品质的重要生物学过程。这2个生物学过程互相依赖,紧密关联。该文论述了紫花苜蓿碳氮高效固定、转运和同化利用的育种新思路,并总结了国内外在二氧化碳的高效固定和转运以及氮素的固定、吸收、转运和同化等方面取得的最新研究进展,以期为饲草高生物量和高蛋白含量分子设计育种提供参考。

Discovery of coesite in eclogite from Keqike Jianggalesayi: new evidence for ultrahigh-pressure metamorphism in South Altyn Tagh, northwestern China

Coesite is a polymorph of Si O2formed at speci?c high-pressure conditions, and its presence in some crustal rocks as relicts marks the exhumation of deep subducted material to mantle depths, thus providing robust evidence for the hypothesis on ultrahigh pressur (UHP) metamorphism [1]. The discovery of coesite and other

Multi-Stage Metamorphism of the UHP Pelitic Gneiss from the Southern Altyn Tagh HP/UHP Belt,Western China:Petrological and Geochronological Evidence

The kyanite-bearing garnet pelitic gneiss from the Jianggalesavi area in southern Altyn Tagh high pressure/ultra-high pressure belt was proved to have been experienced UHP metamorphism (>12 GPa) by the discovery of kyanite and spinel exsolution microstructure in quartz (precursor stishovite). In this study, three stages of retrograded metamorphism (M2-M4) after the UHP metamorphism (Ml) were identified for the UHP pelitic gneiss. The HP granulite-facies stage (M2) was characterized by the mineral assemblage of garnet+kyanite+K?feldspar+nitile+qiiartz±ilinenite, recording the P-T condition of >1.12 GPa and ?850-930℃. The granulite-facies stage (M3) was represented by the mineral assemblage of garnet rim+K-feldspar+sillimanite (SillJ+biotite (Bti)+plagioclase (Pli)+ilmenite+quartz, and confined under P-T conditions of 0.5-0.8 GPa and^770-795℃. The late cooling stage M4 was accompanied by the appearance of fine-grained Pl2, Sill2 and Bt2 in the matrix, and the P-T conditions were 0.4-0.6 GPa and <675℃. A clockvvised P-T path was obtained for the pelitic gneiss in the P-T pseudosection, which showed a deep subduction/collision processes with subsequent exhumation and cooling. Com? bined with the corresponding multistage metamorphic assemblages, the age dating results implied that the zircons from the gneiss have integrated the recording peak metamorphic (Ml,484±3 Ma) and retrograded metamorphic ages (M2 to M3, 450±2 Ma). There was about 32 Ma interval during the first exhumation from the upper mantle depth (>350 km) to the lower crust depth (-40-20 km), resulting in an average exhumation rate of 9.11-9.70 mm/yr. In the southern Altyn Tagh region, the HP and UHP rocks from different areas had identical peak metamorphic ages. Therefore, contemporary UHP and HP rocks with different metamorphic evolutions were recognized coexisting in the same orogenic belt, which can be interpreted by the model of subduction channel. The continental crustal were subducted to different depths along the direction of the subduction channels at ~500 Ma, suffered different grade metamorphism, and then returned to the surface along the subduction channel.

Petrochemistry and Tectonic Setting of the Middle Triassic Arc-Like Volcanic Rocks in the Sayabouli Area,NW Laos

The volcanic rocks from the Sayabouli area in northwestern Laos have been poorly studied. These volcanic rocks are traditionally mapped as the Permian–Early Triassic sequences on the geological map. One basaltic-andesite from the Sayabouli area yields a zircon U-Pb age of 237.7±1.7 Ma, suggesting a Middle Triassic origin. All basalt and basaltic-andesite samples from the Sayabouli area show depletions in HFSEs（e.g., Nb, Ta, Ti） and have high LILE/HFSE ratios, and exhibit the geochemical affinity to the continental arc volcanic rocks and are geochemically similar to the continental arc volcanic rocks from the Phetchabun belt in northeastern Thailand, suggesting a Late Permian–Middle Triassic continental margin in the Sayabouli area of northwestern Laos and Phetchabun area of northeastern Thailand. Our data indicate that the Phetchabun arc volcanic belt through the western Loei sub-belt can be linked to the Sayabouli area in northwestern Laos.

Mixed-cation perovskite solar cells in space

The metal halide perovskite materials demonstrate outstanding performance in photovoltaics because of their excellent optoelectronic properties (1-7)The perovskite solar cells (PSCs) exhibiting outstanding efficiency [8,9], high power-per-weight [10], and excellent radiation resistance[11-13] are considered to be promising for developing the new-generation energy technology for space application.

Reconstruction the Process of Partial Melting of the Retrograde Eclogite from the North Qaidam,Western China: Constraints from Titanite U-Pb Dating and Mineral Chemistry

Retrograde eclogite and garnet amphibolite of the Lüliangshan unit of the Shenglikou area,North Qaidam,were studied with emphasis on rutile and titanite.A special focus is on the formation of rutile and its corona of titanite(Ttn1)in retrograde eclogite and on coarse-grained titanite(Ttn2)from the garnet amphibolite.Using zirconium(Zr)-in-rutile and Zr-in-titanite thermometers,the temperatures estimated for the formation of an early generation of rutile are 823–884℃at 2.5–2.8 GPa,while 812–894℃at 1.3–1.5 GPa are derived for the formation of coronitic Ttn1 in the retrograde eclogite.Therefore,isothermal decompression must have occurred during exhumation,which also has triggered the partial melting of the retrograde eclogite.Ttn2 of the garnet amphibolite has high REE contents and high Th/U ratios,indicating that it is newly grown from a Ti,Ca,and LREE enriched anatectic melt derived from the partial melting of retrograde eclogite.LA-ICP MS U-Pb dating yields a lower intercept age of 423±4 Ma for Ttn2,which is consistent with the granulite-facies metamorphic age of the retrograde eclogite.Moreover,a temperature of 781–823℃at 1.0–1.2 GPa is obtained for Ttn2,which fits the P-T conditions of the HP granulite-facies metamorphic stage(P=1.07–1.24 GPa and T=774–814℃),and documents that the crystallization of the melt occurred at the granulite-facies stage at 423 Ma.The high amount of REE of the garnet amphibolite is a consequence of the formation of Ttn2 from the melt.The contents and ratios of Zr and Hf in rutile and Ttn2 differ from those in the garnet amphibolite,and the whole rock Zr/Hf ratios of retrograde eclogite and garnet amphibolite are both higher than the respective ratios in rutile and Ttn2,suggesting that rutile and titanite cannot be the major carriers of Zr and Hf accounting for the high whole rock Zr/Hf ratios.

Zircon U-Pb Geochronological Evidence for the Evolution of the Nan-Uttaradit Suture in Northern Thailand

The Nan-Uttaradit suture is marked by a narrow N-S trending and discontinuous ophiolite belt in northern Thailand. This suture zone is a mélange composed of gabbro, tholeiitic meta- basalt, andesite and radiolarian chert. Samples of gabbro and meta-basalt in the Nan-Uttaradit suture yield zircon U-Pb ages of 311±10 and 316±3 Ma, respectively, interpreted as the crystallization ages of the rocks, suggesting the Nan-Uttaradit Ocean existed in the Late Carboniferous. Our results indicate that the Nan-Uttaradit Ocean co-existed with the Ailaoshan-Jinshajiang Ocean to the north and was probably an along-strike extension of the latter.

Fabrication of compact and stable perovskite films with optimized precursor composition in the fast-growing procedure

The fast-growing procedure （FGP） provides a simple, high-yield and lead （Pb）-release free method to prepare perovskite films. In the FGP, the ultra-dilute per- ovskite precursor solution is drop-cast onto a hot （-240℃） substrate where a perovskite film grows immediately ac- companied by the rapid evaporation of the host solvent. In this process, all the raw materials in the precursor solution are deposited into the final perovskite film. The potential pollution caused by Pb can be significantly reduced. Proper- ties of the FGP-processed perovskite films can be modulated by the precursor composition. While CH3NH3CI （MACI） affects the crystallization process and leads to full surface coverage, CH（NHz）2I （FAI） enhances the thermal stability of the film. Based on the optimized precursor composition of PbI2.（1-x）FAI.xMACI, x=0.75, FGP-processed planar het- erojunction perovskite solar cells exhibit power conversion efficiencies （PCEs） exceeding 15% with suppressed hysteresis and excellent reproducibility.

Applications of cesium in the perovskite solar cells

Perovskite solar cells have experienced an unprecedented rapid development in the power conversion efficiency（PCE）during the past 7 years,and the record PCE has been already comparable to the traditional polycrystalline silicon solar cells.Presently,it is more urgent to address the challenge on device stability for the future commercial application.Recently,the inorganic cesium lead halide perovskite has been intensively studied as one of the alternative candidates to improve device stability through controlling the phase transition.The cesium（Cs）-doped perovskites show more superior stability comparing with organic methylammonium（MA）lead halide perovskite or formamidinium（FA）lead halide perovskite.Here,recent progress of the inorganic cesium application in organic-inorganic perovskite solar cells（PSCs）is highlighted from the viewpoints of the device efficiency and the device stability.

Petrologic indicators of prograde metamorphism in Paleoproterozoic garnet mafic granulites from the Huai＇an complex, North China Craton

Reconstruction of pressure-temperature-time(P-T-t)paths and thermal regimes are essential for inferring tectono-metamorphic processes involved in the formation of metamorphic terranes.However,the P-T information,especially the prograde evolution is generally preserved incompletely due to the fast intra-or inter-grains diffusion under high-temperatures.It may result

Interfacial stabilization for inverted perovskite solar cells with long-term stability

Perovskite solar cells(PSCs)commonly exhibit significant performance degradation due to ion migration through the top charge transport layer and ultimately metal electrode corrosion.Here,we demonstrate an interfacial management strategy using a boron chloride subphthalocyanine(Cl_(6)SubPc)/fullerene electron-transport layer,which not only passivates the interfacial defects in the perovskite,but also suppresses halide diffusion as evidenced by multiple techniques,including visual element mapping by electron energy loss spectroscopy.As a result,we obtain inverted PSCs with an efficiency of 22.0%(21.3%certified),shelf life of 7000 h,T_(80) of 816 h under damp heat stress(compared to less than 20 h without Cl_(6)SubPc),and initial performance retention of 98%after 2000 h at 80℃in inert environment,90%after 2034 h of illumination and maximum power point tracking in ambient for encapsulated devices and 95%after 1272 h outdoor testing ISOS-O-1.Our strategy and results pave a new way to move PSCs forward to their potential commercialization solidly.

Armigeres subalbatus is a potential vector for Zika virus but not dengue virus

Background:Zika virus (ZIKV) and dengue virus (DENV) are closely related flaviviruses primarily transmitted by Aedes mosquitoes. Armigeres subalbatus is an emerging and widely distributed mosquito, and ZIKV has been detected and isolated from it. However, it is not clear whether Ar. subalbatus could be a vector for ZIKV and DENV or not. In this study, we investigated the infection and transmission of Ar. subalbatus to ZIKV and DENV.Methods:A line of Ar. subalbatus was isolated from Guangdong, China, and further identified by the mitochondrial cytochrome oxidase subunit 1 (COI) gene. The adults of Ar. subalbatus were fed with blood meal containing ZIKV or DENV-2. At 4, 7, 10, 14, and 21 days post-inoculation (dpi), the infections of ZIKV or DENV-2 in the midguts, ovaries and salivary glands were detected and quantified by RT-PCR and RT-qPCR. To assess the transmissibility, suckling mice were exposed to bites of ZIKV-infected mosquitoes, and ZIKV was detected in brain tissue by RT-qPCR and plaque assays. Furthermore, the larvae of Ar. subalbatus were reared in artificial urine containing ZIKV or DENV-2. The infection rates and viral titers of larvae and adults were analyzed by RT-PCR and RT-qPCR, and the viral distribution in larval tissues was observed by immunohistochemistry. Chi-square test and one-way ANOVA analysis were used for assessing the infection rate and viral titer in varied tissues and different time points, respectively.Results:Following oral inoculation, ZIKV but not DENV-2 could be detected in Ar. subalbatus midguts at 4 dpi, ovaries at 7 dpi and salivary glands at 10 dpi. The highest infection rate (IR) of ZIKV was 27.8% in midgut at 7 dpi, 9.7% in ovary and 5.6% in salivary gland at 21 dpi. Eight days after being bitten by ZIKV-positive mosquitoes, ZIKV was detected in three brain tissues out of four suckling mice exposed to bites. ZIKV could be detected in the larvae reared in artificial urine contained ZIKV at a high concentration of 105 pfu/ml and various tissues of adults with a low infection rate (0.70–1.35%). ZIKV could be observed in anal papillae and midgut of larvae at 4 dpi under laboratory conditions.Conclusions:ZIKV but not DENV-2 can infect Ar. subalbatus by blood meal and artificial urine, and the infected mosquitoes can transmit ZIKV to suckling mice by bite. From these findings, we can conclude that the Ar. subalbatus isolated from Guangdong province, China, is a potential vector for ZIKV and should therefore be considered in vector control programs to prevent and control of Zika virus disease.